Regular expressions functions

Function	Support	Notes
`REGEXP_COUNT`	Supported
`REGEXP_EXTRACT_ALL`	Supported
`REGEXP_LIKE`	Supported
`REGEXP_REPLACE`	Supported	Replaces every match, as Snowflake does. With no replacement the matches are removed.
`RLIKE`	Supported
`REGEXP_SUBSTR`	With limitations	The two-argument form only. Snowflake’s later arguments are a start position, an occurrence and parameters, which mean something else here, so a longer call is refused rather than mistranslated.
`REGEXP_SUBSTR_ALL`	With limitations	The two-argument form only, as above.
`REGEXP_INSTR`	Not supported	The position of a match needs the subject twice, once to match and once to locate, and the translation cannot duplicate an expression without evaluating it twice.
`REGEXP`	Not supported